Gaussian mirrors, or variable reflecting mirrors, are characterised by a degree of reflection which slopes radially from the centre of the optic in a Gaussian distribution. These mirrors are used in unstable resonators to produce high quality laser beams with low divergence at high pulse energies. In frequency-doubled systems they are used to achieve a greater pump efficiency. Gaussian mirrors are extremely stable and suitable for high power applications. These optics are based on the principle of a Fabry Perot interferometer, with a position dependant mirror spacing. Dielectric coatings with a defined reflectivity value as a function of radius are generally monochromatic. The Gaussian profile is only valid for a single specified wavelength. Gaussian mirrors are manufactured with high precision usually to customer specifications, by LASER COMPONENTS, one of the few companies worldwide offering this type of mirror.
